Coal



Patented Oct. 23, 1928.

UNITED. STATES I PATENT OFFICE.

GUS'IAVUS J. ESSELEN, JR.,OF SWAMPSGOTT, AND MARK W. WEISS, OF BOSTON, MAS- SACHUSETTS, ASSIGNORS TO THE DELAWARE, LACKAWANNA Ga WESTERN CQAL 00., OF NEW YORK, N. Y., .ACORPORATION OF NEW JERSEY. I

" GOAL.

No Drawing.

This invention relates to carbonaceous fuel of distinctive appearance which distinguishes it from-ordinary fuel of the same class. The invention is applicable to anthracite and bituminous coal in various sizes and to briquettes, coke and the like.

()arbonaceous fuel' of the character described comes to the market in varying qualities and grades. The quality of such fuels cannot be determined by appearance and consequently the consumer is often supplied with inferior grades at the prices of superior grades. Unscrupulous dealers sometimes take advantage of consumers by delivering low grade fuel as the product of some well known producer having a reputation for the high quality of his product and both the consumer and the producer are thus defrauded.

2 It is the object of the present invention to avoid .the possibility of substitution by im- I perficially coated with a suitable coloringv material. The coating need not be uniform nor is it necessary to apply it to all of the exposed surface of the fuel. Coal and similar fuels are handled in bulk and it has been found that a relatively light application of the color medium will give the bulk/fuel a distinctive appearance. The purpose may be accomplished even by applying the color to only a portion of the fuel and by mixing colored with uncolored fuels in suitable proportions.

- For 'the purpose of the invention various 4 materials may be applied in different ways. The coloring materials and the method of applicationshould be such that the fuel'will retain its distinctive appearance duringrepeated handling and exposure to water incident to transportation. ;Numerous coloring materials suitable for the purpose are available.

Among the available materials are watercoloring materials may be employed and such Application filed December 28, 1527. I Serial No. 243,208.

be applied to the fuel in various Ways, for

example, by conveying the fuel through a llquid suspension or solution of the coloring material or by spraying the suspension or solution of coloring material upon the fuel in the conveyor. Another method-of application is to place the fuel in a suitable receptacle containing the suspension or solution or to spray the suspension or solution over a pile of the fuel in such a receptacle. .In each case provision should be made to drain the excess liquid. from the fuel so that waste is avoided- The fuel may then be dried, but this is notnecessary. Such operations may be conducted as a part of the usual Washing procedure. It" is also possible to dust certain colors or pigments with or without: binders on the fuel while the latter is in a moistened condition, the color being fixed when the fuel is dry.

No attempt is made herein to describe every possible adaptation of the invention. The examples hereinafter mentioned are, thyerefore, illustrative of the invention and it is to be understood that various changes and modifications can be made in the nature of the coloring material employed and in the method of application thereof within the scope of the invention.

As a typical example of a satisfactory procedure the pigment commercially known as ultra-marine or Celestial Blue, consisting of a complex compound ofsodium, aluminum, silicon, sulphur and oxygen, may be used with desirable results. The pigment, preferably in finely divided condition, is suspended in water. The proportions of. pigment and water may var over wide limits depending on the metho of application to the fuel and the appearance desired in the product. In general, a ratio of one part, of pigment to from 'one hundred to five hundred parts of water gives satisfactory results. If desired, the character of the suspension may treatment a colloid mi 1 to increase the degree of fineness and improve the dispersion .105 be improved by subjectin the pigment to,

of the pigment in the water. The water employed in preparing the suspension may be pure water or it may be water from the mine in somewhat acid condition. The mine water can be neutralized before the pigment is added thereto or the pigment may carry some acid neutralizing substance 'to correct the acidity of the water. After the suspension has been prepared it is brought into intimate contact with the fuel in any desired manner, for example, by spraying orimmersion. After the fuel has been thoroughly wet with the suspension it is drained to remove the excess thereof. The fuel may be permitted to dry before shipment. Although the more or less complete removal of the water from the fuel probably enhances the permanency of the coating, we have determined that a satisfactory coating may be provided without complete removal of the liquid before shipment or handling of the fuel. No special facilities for drying the fuel are required. The fuel treated as hereinbefore described has the coloring material or. pigment distributed over the surface area and it presents, therefore, a distinctive bluish appearance which differentiates it from fuel which has not been so treated. The coloring is sufficiently permanent to withstand ordinary handling and 1ncidental wetting'of the fuel during transportation. Consequently the consumer can identify the fuel and can be certain, therefore, of the source and quality thereof.

Other igments or colors may be similarly employed? The fuel may be treated, for example, with aqueous suspensions of certain with a colloidal solution of iron hydroxide;

metal oxides, more particularly the oxides of heavy metals. such as zinc oxide, lead oxide, either in the form of litharge or red lead, and iron oxide, either in its pure form or as one of the commercial pigments known as Venetian red, burnt sienna, or Indian red. Other' available pigments are certain chromates of heavy metals, such as chrome yellow, chrome orange or chrome green. These are merely exam les and other oxides and other compo'un s of the metals may be utilized with similar advantage.

Another method of imparting the desired appearance to the fuel consistsm wetting it For example ferric chloride crystals can be dissolved in the proportion of one-half of one part to four parts by weight of crystals to one hundred parts of water. The resulting solution when boiled first forms a recipitate which afterwards disperses to a colloidal suspension. .The fuel may be subjected to treatment with this sus ension either by spraying or immersion whi e the suspension is mamtained at a temperature referably between 50 and-100 C. After t e surplus liquid is drained off the fuel is coated with finel divided iron oxide or hydroxide which ad eres firmly to the surface and is not removed to any extent during the subsequent handling of the fuel.

Another method of carrying out the invention consists in wetting the fuel with an aqueous suspension of a d e lake such as Carmine 40 or Tuscan Red. uscan Red can be produced by precipitating the natural dye hypernic on red iron oxide as a base. This pigment in finely divided form is then sus-v pended in water in the ratio of one part of pigment to from one hundred to five hundred parts of water. After a thorough treatment of the fuel with the aqueous" suspension the surplus liquid is drained away and the fuel is left with a coating of the coloring material;

which adheres firmly to the surface.

It is also possible to use insoluble dyes such as the so-called indanthrene colors. As an example a suspension of one partof Ponsol Red Violet QBNX paste (du Pont) in one hundred parts of water may be applied to the 'fuel by spraying or immersion. When the" surplus-liquid is drained from the fuel a coating of the dye will remain. Another example of the method consists in wettin the fuelwith a suspension of a finely divided metal such as powdered. aluminum, powdered copper or commercial bronze powder in, a-dilute aqueous solution of a suitable binder. Sodium silicate'may be used, for example, with some pigments. The

ratio of powdered metal to the solutionmay be, for example, one part of the owder to from one hundred to five hundre parts of solution, depending upon the effect to be produced. The fuel is treated by spraying or immersion with this sus ension andthe surplus solution is drain away, leaving the fuel coated with the metallic powder. The

ermanency of the coating may be increased y treatin the coated fuel-with a very dilute solution 0 'sul huric acid or equivalent agent such as aluminum sulphate to harden the sodium silicate, film.

Certain dyes which are insoluble in: water can be dissolved in oils such. as gasoline, kerosene, or other hydrocarbon oil s, and utilized for the purpose of thepresent invention. For example, a 0.5% solution of thed'ye Oil Blue Paste, of American Aniline Products Com any, or a 1% solution of the dye Oil Scar et 6G, of National Aniline and Chemical Company, can be dissolved in gasoline or kerosene and applied to the fuel by spra in or by immersion as hereinbefore descri When the surplus liquid is' -ft'rithdrawn and the solvent'h'as evaporated thefue'l is left with a superficial coating of a blue or red. color which is not affected by water. A nonvolatile oil may bev usedwin place of the'vehicles mentioned, leavin a colored oily coating on the fuel. The uel thus colored can i be distinguishedfrom ordinary fuel.

Similarly, solventssuch as alcohol csin be utilized with dyes soluble in alcohol but insoluble in water in about the same proportions. Thus, an alcohol solution of Oil Blue Paste or Oil Scarlet 6G can be applied to the fuel by spraying or immersion and the surplus liquid can be withdrawn. The alcohol evaporates readily, leaving the superficial color on the fuel which serves to distinguish it. Denatured alcohol can be used or ordinary 95% grain alcohol or absolute alcohol, although the cost of the latter-solvents prohibitsthe use, thereof in ordinary commercial operations. Water-insoluble dyes which are soluble in acetone, benzol, toluol, etc., can be applied similarly to the fuel.

- 'A class of dyes known as basic dyes may be applied to the fuel to provide a waterproof color by subjecting the dyes to the actionof a mordant such as tannic acid. The color can be applied in either of two ways. For example, the fuel is first wet witha solution of tannic acid and water, a 5% solution being suitable, and the fuel is then dried. It is wet with a water solution of a basic dye,-

for example, a 0.5% solution of Basic Blue 2B, and again dried. The dye is fixed by the tannic acid and is .not affected by water Other dyes of a similar character can be used likewise, for example, Basic Violet B, Cryst'al Violet, Safranine A, Phosphine and Rhoremains in suspension and the suspension can be used by spraying or immersion to color the fuel. The precipitated lake acts as a pigment and is depositedon the surface of thefuel, ,After the fuel is dry the coloring material is not affected by water. As an example of this operation, a 5% aqueous solution of Basic Blue 2B is mixed with a 5% aqueous solution of tannic acid in the proportions of approximately 1:4. The resulting blue lake suspension is then applied to .the fuel which is permitted to dry, leaving a bright blue color on the surface of the fuel. A. red color can be imparted to the coal by mixing a 1%,solution of Safranine' A with a 5% solution of tannic acid in equal proportions. The red lake thus produced is applied to the fuel in the manner described and imparts a superficial coating of red color thereto.

While commercially pure tannic acid is preferably employed, it is possible to use various extracts containing tannin, such as quebracho extract, chestnut extract, extract of nut galls, etc-., as mordants.

The basic dyes mentioned can be used similarly with soaps such as commercial rosin size (sodium resinate) or commercial soap.

For example, the fuel is first immersed in a solution containing 5% of commercial rosin size by weight. Preferably, though not necessarily, the fuel is dried. It is then treated with a 0.5% solution of Basic Blue and is thereby given a water-proof coating of blue color. The fuel can be colored similarly in a single operation by mixing a 1% water solution of Basic Blue 2B With'a solution containing 5% of commercial rosin size by weight in equal proportions. The dye is precipitated as a finely divided compound which can be maintained in suspension and applied thus to the fuel. When the fuel is dry a permanent Water-proof colored coating is formed on the surface of the fuel.

Ordinary soap may be used in place of rosin size. For example, the fuel is first immersed in a solution containing 2% by weight of soap chips and dried. It is given a permanent color by immersing 'it in a 0.5% solution of Basic Blue. Alternatively, the dye solution and the soapsolution may be mixed and the resulting suspended color can be applied to the fuel by immersion. or spraying. Pure salts of fatty acids such as sodium or potassium oleate, palmitate or stearate can be used in place of ordinary soap pr rosin size but the cost of these materials prohibits the use thereof in commercial operations.

The pigment or color may as hereinbefore indicated be applied to the fuel by blowing it thereon in a stream'of air, the fuel being first moistened with water or with a solution containing, for example, sodium silicate. Conveniently the fuel may be caused to'travel on a suitable conveyor past the air blast which carries a pigment such as finely divided metal of the kind hereinbefone described. The moistened fuel is thus provided with a superficial coating of the pigment which is more or less permanently attached thereto and serves to impart to the fuel a distinctive appearance. I

As the surface of the coal is irregular and includes crests and valleys, the coloring material ap lied by the processes hereinbefore describe will, in many cases',"tend. to settle in the valleys where it will remain in substantial amounts, and the crests or higher surfaces will be left substantially. free from the coloring material, thereby causing the surface of the coal to be characteristically, altered without causing it to lose its general appearance as such.-

wouldprevent the utilization thereof in the The numerous examples hereinbefore set forth are indicative of the wide range of pos commercial application of the invention. Nevertheless, innumerous instances the cost of coloring the fuel can. be reduced to a point which permits the effective use thereof to accomplish the pur ose of distinguishing fuel of high qualit rom the ordinary or poor 7 grades of fue which reach the market in large quantity.

g It is unnecessary to coat all of the fuel. A quantity thereof may be coated in the manner and with any of the coloring materials hereinbefore described, andsuch coated fuel may be mixed in suitable proportions with other-fuel to impart to the fuel the desired characteristic appearance. The proportions employed in fuel will receive such product rather than inferior substitutes therefor. In avoiding substitution-the producer as well as the consumer is benefitted because the producer can thus maintain the good-will based upon the production and sale of superior fuels.

1. Coal having an irregular surface includ ing crests and valleys, said coal having: coloring material deposited in the valleys of the surface thereof in an amount sufiicient to characteristically alter the appearance of the coal'in bulk, but insufficient to cause the coal to lose its general appearance as coal.

2. Coal partly coated over its entire surface with coloring material, said coloring material being applied in an amount suflicient to characteristlcally alter the appearance of the coal in bulk but insuflicient to cause the coal to lose its general appearance as coal.

in testimony whereof we aflix our signatures.

GUSTAVUS J. ESSELEN, JR. MARK W. WEISS. 

